Recently, song Dongpo research group of Tianjin University successfully developed photonic crystal pigments with beautiful structural colors. This new type of photon pigment has the advantages of good biosafety and biodegradability, and is expected to bring subversive technological innovation to the beauty industry. This achievement has been published in the authoritative journal "German Applied Chemistry". It is reported that the project has been supported by the national key research and development plan and the National Natural Science Foundation of China.

In daily life, plastic beads are often used as fillers, film formers, thickeners and suspensions in nail polish, facial cleanser, sunscreen, liquid foundation and other products. After people use, the plastic beads are easily discharged into the sea through the sewer, sucked into the body by marine organisms, and then enter the human body through the food chain. Therefore, there is an urgent need to develop non-toxic and degradable plastic microbeads.

Song Dongpo's research group successfully developed photonic crystal pigments with beautiful structural colors by using the principle of ordered spontaneous emulsification. This new type of photon pigment is prepared from biodegradable polyester materials such as polylactic acid. The photon microbeads can perfectly replace the plastic microbeads and play the role of exfoliating and massaging the skin.

The team selected E. coli, Chlorella pyrenoidosa, Daphnia magna, zebrafish and other typical aquatic organisms of different nutritional levels for rigorous environmental safety assessment. The experimental results show that the new photonic crystal pigment does not show any toxicity and has no adverse effect on the behavior of the above-mentioned organisms, which proves that this kind of material can be used in cosmetics and other industrial products and is environmentally friendly.

It is particularly worth mentioning that the internal nanostructure of this new type of photonic pigment is "opal structure", which can form a "structural color" similar to butterfly wings and peacock feathers. The "structural color" has the characteristics of beautiful and lasting, and can respond to color change. Under different light angles, it can reflect different colors, thus producing a color change effect that traditional pigments do not have.

"This new type of photon pigment is expected to widely replace non degradable plastic beads and synthetic pigments in cosmetics and personal care products, and can also be used as an ultraviolet reflector to replace nano titanium oxide in sunscreen." Song Dongpo said, "after being discharged into the water body, it can spontaneously degrade into non-toxic lactic acid within a few months, and will not have a negative impact on the aquatic ecosystem. It will solve the environmental pollution caused by the use of cosmetics to a large extent."